It may be possible but NOT necessarily a good idea. 1-1/2 to 2 lbs. per week is generally considered a safe rate of weight loss. If you starve yourself in order to lose weight, your body will began to eat muscle tissue 'cuz it's easier to burn than fat. Heart muscle often suffers and this damage is a frequent cause of death for anorexics and bulimics. Fat actually requires some carbohydrates to burn! Eat whole grains and read labels: you can deduct each gram of fiber from the total carbs in the food you eat (net carbs). Not eating protein for 3 weeks can also cause muscle weakening. Check with your doctor and don't place your faith in fad diets. There's always a new one out there because all the others didn't work to KEEP the weight off. DO NOT drink only tea: it is a diuretic and you will end up dehydrated. Severe dehydration can also be fatal. Drink plenty of water: it'll actually help you to lose weight.